ASSOCIATIONS BETWEEN HEALTH DISORDERS DURING 2 CONSECUTIVE LACTATIONS AND CULLING IN DAIRY-COWS

Data from an observational study, carried out from 1986 to 1990, were used to quantify the effects of 15 main health disorders during two consecutive lactations on the risk of culling in the latter one. The study population consisted of 47 commercial Holstein herds from western France, comprising 4123 cows. Logistic regression was used to assess the relationship between health disorders and culling within and after 45 days post-partum. Adjustments were made for year, month of calving, parity, breeding value for milk, best of the two first milk production records and reproductive performance. Effects of interactions were investigated. Herd effect was accounted for using random effect models. Few diseases from the previous lactation were related to culling in the current lactation. Non-traumatic udder disorders, teat injuries, mastitis, high milk somatic cell count, abortion and metritis from the previous and current lactations were dominant with respect to culling within and after 45 days post-partum. The risk of being culled within and after 45 days post-partum increased with higher parity and lower breeding value for milk. Lower previous 305-day milk production and poor reproductive performance increased the risk of culling within and after 45 days post-partum respectively.